Means for automatically varying the stroke of pump rods or like reciprocating members



Aug. 11, 1953 E. F. N. M GAUCHIE MEANS FOR AUTOMATICALLY VARYING THESTROKE OF PUMP RODS OR LIKE RECIPROCATING MEMBERS 2 Sheets-Sheet 1 FiledJuly 25, 1951 1;? ven'lof EiF/YMcgczuch Aug. 11, 1953 E. F. N. MGAUCHIEMEANS FOR AUTOMATICALLY VARYING THE STROKE OF PUIIP RODS OR LIKERECIPROCATING MEMBERS Filed July 25, 1951 2 Sheets-Sheet 2 Patented Aug.11, 1953 MEANS FOR AUTOMATICALLY VARYIN G THE STROKE OF PUMP RODS ORLIKE RECIPROCATING MEMBERS Ernest Francis Naismith McGauchie, Bentleigh,Victoria, Australia Application July 25, 1951, Serial No. 238,557 InAustralia August 24, 1950 12 Claims.

This invention relates to improved means for automatically varying thestroke of pump rods or like reciprocating members and is particularlyapplicable to, though not necessarily limited to, the pump rods ofwindmills.

The invention relates to an improvement on that kind of apparatusutilizing hydraulic or fluid operated means for varying the stroke of apump or like reciprocating part according to circumstances, such as forexample as disclosed in my prior Patent No. 2,135,011. More specificallythe present invention relates to improvements in the construction andoperation of the general kind of apparatus as disclosed in my saidprevious specification.

It is an object of the present invention to devise an improved means forautomatically varying the stroke of pump rods or like reciprocatingmembers characterised by a relatively simple and compact constructionand capable of more efficient operation under various conditions of use.

In apparatus according to said prior specification a valve control wasoperated by wind velocity actuating a wind vane and the presentinvention proposes an improved means for the purpose specified andincluding a valve which is automatically controlled and operatedaccording to the operative speed of the driving section of a pump rod.

The invention may be said to comprise improved means for automaticallyvarying the stroke of the driven section of a pump rod or the like,having driving and driven sections, comprising major and minor cylindersmounted in longitudinal alignment, the minor cylinder being stationarilymounted by one end and provided at its remote end with a stationarypiston or plunger having an aperture longitudinally therethrough andencompassed by a movable barrel constituting the major cylinder, themajor cylinder being adapted to be reciprocated by the driving sectionof the rod, a valve device mounted in the otherwise closed end wall ofthe major cylinder which is arranged to be immersed in a fluid, and apiston or plunger within the minor cylinder operatively connected to andadapted to impart reciprocating motion to the driven section of the rod.

In order that the invention will be more readily understood referencewill be made to the accompanying drawings which show a practicalembodiment of the invention which is at present preferred.

Referring to the drawings which form part of this specification:

F r 1 is a verti al 5 9 1 V ew .03 the .em-

bodiment with portion of a casing broken away.

Figure 2 is an elevation similar but unsectioned to the view shown inFigure 1.

Figures 3 and 4 are semi-diagrammatic views showing the embodiment intwo phases of operation.

Referring now to Figure 1 the driving section of a pump rod is adaptedto be connected to a yoke I by bolt 31a and the driven section of therod is adapted to be connected to the lower ends of a pair of connectingbars 2 which depend from a uniting yoke 3 (the connection of the drivingsection DSI of the pump rod and driven section D82 of the rod is bettershown in Figure 3).

A pair of rods 4 extend from the yoke I to the lower end wall 20 of amajor cylinder 6 and are secured to the latter.

The rods 4 and cylinder 6 are vertically reciprocab-le and to enablesuch a movement the yoke 3 is provided with bearing apertures I throughwhich the rods may reciprocate.

A minor cylinder 8 is mounted in longitudinal alignment with the majorcylinder 6 and the upper end of the minor cylinder 8 is secured to abracket 9 which is adapted to be mounted and secured to a windmill frameor like fixed structure. Thus the minor cylinder 8 is stationarilymounted. Bearing apertures I I are provided in the bracket 9 throughwhich the rods 4 are freely reciprocable.

Abutments or flanges 5 are formed on each of the rods 4, positioned soas approach closely but not actually engage against the underside of thebracket 9 when the driving section is at its upper limit of stroke.

The lower end of the minor cylinder is provided with a piston or plungerI2, with an aperture I3 therethrough, which piston is a neat fit in andencompassed by the major cylinder 6. For this purpose the piston orplunger I 2 may be provided with cup leathers, rings or such devices toform a substantially fluid tight fitting in the cylinder.

A piston or plunger I 4 is provided in the minor cylinder to bereciprocable therein and this piston I 4 may also be provided with cupleathers, rings or the like to form a substantially fluidtight fit. Thepiston I4 is secured to the lower end of a rod I6 the upper end of whichis secured to the yoke 3.

A valve device I! is mounted in the lower end wall 20 of the majorcylinder '6.

The valve device I1 is desirably of the flat seating kind, i. e., isprovided with an annular facing adapted to-seat on an annular seating. Arelatively small bleed indent or recess, indicated at I8, is provided onthe facing of the valve for a purpose later indicated.

The valve is reciprocable axially within an aperture l9 formed in theend wall of the major cylinder and is influenced towards an opencondition by a spring or like member, but means are provided to ensurethat the valve will be positively and mechanically influenced to aclosed state under certain conditions.

Such means includes a bar 2| (see Figure 2) engaged in a slot in thestem of the valve and mounted on the lower end of a rod 22 the upper endof which is adapted to be engaged and influenced by a pivoted arm 23provided at its outer end with a cam follower member 24 which is adaptedto engage on a ramp or cam face strip 26, constituting a stationary rampmember, which is preferably adjustable for length according to workingconditions required.

The rod 22 and the pivoted inner end of the arm 23 are mounted on andcarried by one of the rods 4 (the rod 22 being axially movable withinbearing holes in wall 20 and in lug 4a outstanding from the rod 4) andare reciprocable with the major cylinder and those rods 4. When theselatter parts are approaching the upper end of a stroke the cam follower24 will engage the ramp or cam face 26 and thereby cause the rod 22 tobe moved downwardly and effect a closure of the valve device IT.

The rod 22 is provided with a compression spring 21 and a screw and anut adjustment device 28, the spring being to ensure that the rod isnormally influenced upwardly, and the valve opened, and the screw andnut device being to enable an adjustment of the operative effect of thespring on the valve IT, in accordance with varying conditions ofoperation in service. Adjustment means, indicated at 25, are alsoprovided on rod 22 by which means the maximum displacement of the valveabove its seat may be varied in accordance with requirements.

Thus the major cylinder may be reciprocated with the rods 4 by thedriving section DSI of the pump rod, and that movement of the piston Mwill be conveyed by the rod l6, yoke 3 and connecting bars 2 to thedriven section D82 of the pump rod.

Means such as compression springs 3| may be mounted on the upper side ofthe bracket 9 to provide a resilient stop for the yoke member 3 anddriven section of the pump rod when it approaches its lower extremity oftravel.

A bridge member 32, slidable on the rods 4, has a downwardly dependingstem 33, encompassed by a spring member 34 which is adapted to beaccommodated in a tubular portion N3 of the rod [6. The upper centralsurface of the bridge member 32 is provided with a rubber or likeresilient insert 36 which is adapted to engage on an abutment 37 on theunderside of the yoke I, the purpose of these parts being to provideresilient means to positively influence the yoke 3, rod [6, piston M,and the driven section DSZ of the pump rod downwardly when the drivingsection DSI (including the yoke i) is travelling downwardly. Undernormal conditions the driven section will move downwardly by gravity.

A casing 38 is secured to and depends downwardly from the bracket 9 andthe casing is adapted to contain a quantity of oil or other suitablefluid up to a level to ensure that the lower end of the reciprocablemajor cylinder is at all times immersed therein. The bars 2 connectedCir to the driven section DSZ of the pump rod are mounted externally ofthe casing.

Ventilating ducts (for clarity not shown in the drawings) are formedthrough the bracket 9, and a cup-like wall 39 extends around the upperportion of the bracket 9 to restrain oil which may be pumped to abovethe bracket from running onto the exterior of the casing, and openingsare provided through the bracket to drain such oil back into theinterior of the casing.

The bore diameters of the major cylinder 6 and the minor cylinder 8 aredesirably in the approximate ratio of 1%:1 respectively.

In operation, and referring more particularly to Figure 3 with theassumption that the driving section DSI of the pump rod, and the majorcylinder, are moving upwardly at an appropriate speed the velocity orflow of oil or fluid escaping from a lower chamber C in the majorcylinder will influence the valve IT towards a closed condition byhydrodynamic forces and oil or fluid will be displaced through theaperture i3 into a chamber D in the minor cylinder above the piston [2.Depending upon the speed and power of the driving section so will valveH be influenced more or less quickly into a seated condition, againstthe influence of spring 21', and thus less or more fluid will escapethrough the valve I! back into the reservoir R in the casing and more orless fluid will be displaced into the chamber D to move the piston orplunger 14, and the driven section DSZ of the pump rod, upwardly.

Thus, when the driving section DSI moves upwardly relatively quickly,the valve ll will be caused to be seated promptly (as shown in Figure 3)enabling maximum displacement, of fluid, length of stroke, speed andpower to be imparted in an upward direction to piston 14 and the drivensection DSZ of the pump rod.

When the driving section DSI is moving upwardly relatively slowly, aswill be the case when actuated by a windmill driven by a relatively lowvelocity wind, a major proportion of the oil or fluid will escape fromthe chamber C through the open valve ll (which in those circumstanceswill be open by influence of spring 2?) and thus no movement will beimparted to the driven section DS2 of the pump rod until such time asthe driving section approaches its upper end of travel whereupon the camfollower 24 will engage on the ramp 26, cause the valve I! to be seated,and a limited but positive impulse will be imparted to the drivensection DS2 of the pump rod.

Referring now to Figure 4, and assuming that the driving section of thepump rod and the major cylinder are moving downwardly, the drivensection of the pump rod and operative parts connected thereto willnormally be influenced downwardly by gravity, but to ensure positivedownward movement of those parts if not effected by gravity the abutment31 (see Figure 1) on the driving section will engage with the resilientinsert 36 on the bridge member 32 and influence the rod [6, connected tothe driven section, downwardly by medium of the spring 34.

Under normal operative conditions, the weight of the driven shaft whenmoving downwardly will maintain pressure on the fluid in chambers C andD, and the valve ll will be retained seated by hydraulic pressure in thechambers C and D until such time as the driven section reaches its lowerextremity of stroke when its Weight will be supported by the springs 3|.If the driving section is positively influencing the driven sectiondownwardly pressure will be released in chambers C and D and the valvewill open under the influence of spring 21 and permit fluid to pass fromreservoir R into chambers C and D, which chambers will always be chargedwith fluid when in operation.

In the event that the driving section should become stationary during anupward stroke under load (i. e. by stopping of the windmill, forexample) with the valve l1 seated the bleed indent I8 on the face of thevalve will permit fluid to slowly escape from the chamber C into thereservoir R, and thus enable the piston M and the driven section of thepump rod to move slowly downwardly independently of the driving sectionand effect its downward stroke, whereupon in such circumstances, andpressure of fluid in the chamber C being relieved, as the driven sectionengages the springs 3! which will then support the weight of the drivensection, the valve I! will open under the influence of spring 2'1. Thus,the driving section will not be handicapped by a load when it resumes anupward stroke.

A safety valve device of any suitable kind, indicated at 4!, may beprovided in the lower end wall 20 of the major cylinder so that in theevent of an abnormal pressure developing in the major cylinder, fluidmay escape through the safety valve back into the reservoir, thusobviating any damage to operative parts.

The lower end of the rod 15, carrying the plunger I4, is preferablyprovided with an aperture 42 therethrough, the lower end having arelatively minute bleed hole 43 in communication with chamber D. Thebleed hole and aperture, which is in communication with the upperportion of the minor cylinder 8 and open to the atmosphere, through amanually operable valve device 45, are proposed to ensure that any airwhich may be trapped in the chamber D, particularly when the apparatusis initially charged with oil and started in operation, may be permittedto escape and thus obviate any air lock in chainbers C and D with thepossibility of consequent inefliciency of. the apparatus in operation.Ihe lower end of the rod 16, around the bleed aperture 43, is providedwith a protective wire gauze strainer 44 to prevent any foreign matterwhich may be in the fluid from blocking or restricting the aperture 43.

Suitable covers (not shown) to prevent or minimize the entry of dust andrain into the mechanism of the apparatus may also be provided.

It is to be understood that modifications may be made without departingfrom the spirit and scope of the invention as defined by the appendedclaims.

Having now described my invention, what I claim as new and desire tosecure by Letters Patent is:

1. Improved means for automatically varying the stroke of the drivensection of a pump rod or like reciprocating member having driving anddriven sections, comprising major and minor cyl inders telescopicallyarranged in relation to each other in a substantially vertical attitude,a stationary support, means for securing the minor cylinder to saidstationary support, a piston stationarily mounted at the lower end ofsaid minor cylinder, said piston having an aperture extendinglongitudinally therethrough, said major cylinder being a close slidingfit around said piston, means connecting the major cylinder to saiddriving section of the rod so that the major cylinder will reciprocatewith the latter, the lower end of said major cylinder being closed withthe excep- 6 tion of an aperture in its base, a valve device mounted insaid aperture, a casing encompassing the lower portion of said majorcylinder for containing a body of fluid, the lower end of said majorcylinder being at all times immersed in said fluid, a pistonreciprocable within the minor cylinder, and means for operativelyconnecting said piston to the driven section of the pump rod.

2. Improvedmeans as claimed in claim 1, in which means are provided formounting said valve device in said aperture in the base of said majorcylinder so that said valve device is reciprocable axially within saidaperture, and resilient means for yieldingly urging said valve devicetowards an open position.

3; Improved means as claimed in claim 1, in which means are provided formounting said valve device in said aperture in the base of said majorcylinder so that said valve device is reciprocable axially within saidaperture, resilient means for yieldingly urging said valve devicetowards an open position, and adjustment means for adjusting theoperative effect of the said resilient means on the valve device toprovide for variable operative conditions under which the apparatus maybe called upon to operate.

4. Improved means as claimed in claim 1, in which valve-closing meansare provided to positively seat said valve device when the majorcylinder and driving section of the rod are moving upwardly relativelyslowly and approaching the upper limit of a stroke, said valve-closingmeans including a cam follower member pivoted on a part fixed relativelyto the major cylinder and reciprocable therewith, a stationary rampmember mounted on said stationary support, the cam' follower memberbeing adapted to engage said stationary ramp member towards the upperlimit of travel of the major cylinder, a rod for actuation by the camfollower member when the latter engages said stationary ramp member, aspring member for opposing actuation of the rod, and operativeconnections between the rod and the valve device to effect a seating ofsaid valve device against the influence of said spring member when thesaid rod is actuated by the cam follower member. a

5. Improved means as claimed in claim 1, in which valve-closing meansare provided to close said valve device when the major cylinder anddriving section of the rod are moving upwardly relatively slowly andapproaching the upper limit of a stroke, said valve-closing meansincluding a cam follower member pivoted on a part fixed relatively tothe major cylinder and reciprocable therewith, a stationary ramp membermounted on said stationary support, the cam follower member beingadapted to engage said stationary ramp member towards the upper limit oftravel of the major cylinder, a rod for actuation by the cam followermember when the latter engages said stationary ramp member, a springmember for opposing actuation of the rod, and operative connectionsbetween the rod and the valve device to efiect a seating of said valvedevice against the influence of said spring member when the said rod isactuated by the cam follower member, and in which an adjustable screwand nut arrangement is provided mounted on the rod and operativelyassociated with the spring member, said adjustable screw and nutarrangement constituting means for adjusting or varying the operativeeffect of the spring member on the valve device.

6. Improved means according to claim 1, in

7 which said valve device is provided with a relatively small bleedmeans.

'7. Improved means as claimed in claim 1, in which resilient means areprovided for yieldingly urging said valve device towards an openposition, the strength of said resilient means bein co-related to thosehydrodynamic forces of th fluid which tend to influence the valve devicet wards a seated position at an optimum speed of the driving section sothat said valve device Will automatically control the amount of fluidwhich can pass said valve device into the minor cylinder to influencethe piston reciprocable therein to transmit power from the drivingsection of the pump rod to the driven section thereof, in accordancewith the operative speed of the said driving section.

8. Improved means as claimed in claim 1, in which a resilient member isprovided interposed between the driving section and the driven sectionand constituting means to positively force the driven section downwardlywhen the driving section is travelling downwardly.

9. Improved means as claimed in claim 1, in which a resilient member isprovided mounted on the stationary support for engagement by the drivensection of the pump rod to thereby limit downward movement of saiddriven section.

10. Improved means according to claim 1, in

which said stationary support comprises a bracket adapted for connectionto a windmill frame, the minor cylinder being stationarily mounted onsaid bracket and the said casing depending from said bracket, andwherein said major cylinder is entirely mounted and reciprocable withinsaid casing.

11. Improved means according to claim 1, in which said stationarysupport comprises a bracket adapted for connection to a windmill frame,the minor cylinder being stationarily mounted on said bracket and thesaid casing depending from said bracket, and in which said majorcylinder is entirely mounted and reciprocable within said casing, and acup-like wall is formed on the upp side of the bracket adjacent theupper extremity of the casing.

12. Apparatus for automatically varying the stroke of the driven sectionof a pump rod or like reciprocating member having driving and drivensections, comprising a bracket adapted to be supported by a fixedstructure, a minor cylinder attached at its upper end to the bracket, astationary piston mounted at the lower end of the minor cylinder, saidstationary piston having an aperture extending longitudinallytherethrough, a major cylinder encompassing said stationary piston, aconnecting member connecting said major cylinder to the driving sectionof the pump rod to axially reciprocate the major cylinder, a pistonmounted and reciprocable within the minor cylinder, a member connectingsaid last-mentioned piston to the driven section of the pump rod toimpart reciprocatory motion thereto, a valve device mounted in the lowerend of the major cylinder, an outer casing supported by and dependingfrom the bracket for containing a body of fluid in which the lower endof said major cylinder will be immersed at all times, a resilient meansfor yieldingly urging said valve device towards an open condition,adjustment means for adjusting the operative effect of the saidresilient means in the Valve device, said valve device being influencedquickly into a seating condition by hydrodynamic forces of the fluidaccording to an appropriate speed and power developed by the drivingsection, and mechanical valve-closing means to effect seating of thevalve when the major cylinder and driving section of the rod are movingupwardly relatively slowly and approaching the upper limit of theirstroke.

ERNEST FRANCIS NAISMITH MCGAUCHIE.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 662,515 Yale Nov. 27, 1900 1,828,679 Pieper Oct. 20, 19312,135,011 McGauchie Nov. 1, 1938 2,446,862 Wilders Aug. 10, 1948 FOREIGNPATENTS Number Country Date 6,185 Great Britain Mar. 14, 1906

